FLY FISHING FOR TROUT AND GRAYLING. 313 



every urchin who has * paidlit in the burn,' where it is found 

 cuddling cannily under the shady side of a stone. Elderly 

 trout pursue the loach most greedily, and seem to prefer it even 

 to the minnow. I have never known the experiment tried o' 

 introducing it into a trout stream, though I have known several 

 in which it was quite at home. But from the great variety of 

 brooks in which it thrives, ranging from Scotland to Devon- 

 shire, I think such an experiment would be well worth trying 

 It would succeed, I feel assured, wherever there are plenty of 

 gravelly shallows, broken by stones from the size of a fist to 

 that of a brickbat. 



The ' miller's thumb,' or ' bull-head,' has nearly the same 

 habits as the loach, and is relished by trout in spite of his spiny 

 shoulders. 



Again, there are certain small crustaceans, popularly known 

 as 'fresh- water shrimps' {^CainiiiarincB, I think, is their learned 

 name), which are found in fine sand in sundry streams known 

 for the firmness and flavour of their trout. But of the habits 

 of these queer little wrigglers I know nothing. I have merely 

 a general impression that they ought to be classed among 

 ' movable feasts ' for trout, with a vague hope that some 

 brother angler with equal zeal and more knowledge will succeed 

 in introducing them to new waters for the fattening of under- 

 fed fish. 



It is well known that small shell fish form a large part of 

 the diet on which fish thrive in many celebrated lakes. Loch 

 Leven may be mentioned as a case in point, though the area 

 of the weed beds from which its trout pick their favourite food 

 has been greatly reduced. The gillaroo seems to owe his 

 special excellence to the same ' hard meat,' and I have little 

 doubt that his distinctive gizzard is merely an organ developed 

 in the course of many generations to aid in the crunching of 

 shell fish. But I have never seen it suggested that the trout of 

 our brooks and rivers have the same taste for these rough mor- 

 sels. There is, however, one genus — that of Limnceus — several 

 species of which might, I think, do good service in a trout 



